1. Field of the Invention
This invention relates to a coiler-furnace unit comprising a coiler for coiling a metal strip, a sleeve, which comprises heating means for heating the coiler mandrel and is adapted to be axially displaced over the coiler mandrel, and a heat-insulating shell associated with said sleeve.
2. Description of the Prior Art
In order to ensure that strip will be economically preheated without a formation of additional scale, it is known from Austrian Patent Specification No. 373,290 to heat the coiled strip via the coiler mandrel rather than by means of hot gases fed into the coiler-furnace unit. For this purpose a sleeve is provided, which comprises means for heating the coiler mandrel and which is pushed over the coiler mandrel before the strip is coiled. By that sleeve the coiler mandrel is heated up so that the heat stored by the coiler mandrel can be transferred to the strip when the latter has been coiled. The sleeve is provided with a heat-insulating shell in order to ensure that a dissipation of radiant heat, e.g., to the strip-guiding means, which are movable into engagement with the coiler mandrel, will be avoided as the coiler mandrel is heated up. But in spite of that measure it is not possible to avoid a dissipation of radiant heat because the sleeve is removed from the coiler mandrel when the same has been heated up and a considerable heat quantity is then transferred to the coiled strip to the strip-guiding means.